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Direct CIII–HflB interaction is responsible for the inhibition of the HflB (FtsH)‐mediated proteolysis of Escherichia coli σ 32 by λCIII
Author(s) -
Halder Sabyasachi,
Banerjee Subhamoy,
Parrack Pradeep
Publication year - 2008
Publication title -
the febs journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.981
H-Index - 204
eISSN - 1742-4658
pISSN - 1742-464X
DOI - 10.1111/j.1742-4658.2008.06610.x
Subject(s) - proteolysis , escherichia coli , bacteriophage , chemistry , lysogenic cycle , escherichia , peptide , biochemistry , biology , microbiology and biotechnology , enzyme , gene
The CIII protein of bacteriophage lambda exhibits antiproteolytic activity against the ubiquitous metalloprotease HflB (FtsH) of Escherichia coli , thereby stabilizing the λCII protein and promoting lysogenic development of the phage. CIII also protects E. coli σ 32 , another substrate of HflB. We have recently shown that the protection of CII from HflB by CIII involves direct CIII–HflB binding, without any interaction between CII and CIII [Halder S, Datta AB & Parrack P (2007) J Bacteriol 189 , 8130–8138]. Such a mode of action for λCIII would be independent of the HflB substrate. In this study, we tested the ability of CIII to protect σ 32 from HflB digestion. The inhibition of HflB‐mediated proteolysis of σ 32 by CIII is very similar to that of λCII, characterized by an enhanced protection by the core CIII peptide CIIIC (amino acids 14–41 of λCIII) and a lack of interaction between σ 32 and CIII.